1. Technical Field
The present disclosure relates to a freshness estimation method, a freshness estimation apparatus, and a non-volatile recording medium for estimating the freshness of a fish as food.
2. Description of the Related Art
Hitherto, methods for objectively estimating the freshness of a fish as food have been suggested. For example, according to Japanese Unexamined Patent Application Publication No. 7-213488, a crystalline lens of a fish is irradiated with light, and the freshness of the fish is determined by analyzing the spectrum of the reflected light. According to Japanese Unexamined Patent Application Publication No. 2010-268792, a surface of a piece of meat is irradiated with light, and the amount of bacteria on the surface is estimated by using the absorbance.
However, Japanese Unexamined Patent Application Publication No. 7-213488 does not describe a specific criterion for judgment using a spectrum, and thus the effectiveness of freshness estimation is unclear.
On the other hand, the technique disclosed in Japanese Unexamined Patent Application Publication No. 2010-268792 is effective for locally estimating the freshness of a piece of meat to be eaten, but is incapable of estimating the freshness of an entire fish.